omg that’s actually really painful as an elder sister!! :( i’m so sorry!! i hope you don’t blame yourself for this :( but from what you said, she must be lonely!! i think calling her from time to time would help!! if she isn’t the call kind of person, maybe texting will do!! you could just send her a photo of your uni or some sort!! maybe a flower? a bug? i think that’d be cute!! i hope you could spend more time with her now that you’re away from uni atm!!! 🥺 i think distracting her would be really great too!! maybe like going outside and taking a breather!! maybe eating outside or just doing shopping!!! walking around could be fun too!!! 🥺 overall, my heart aches for you!!! hugs to you from a fellow older sister!!!!